Species

Oreobolus impar

Etymology

Oreobolus: mountain clump
impar: dissimilar (upper and lower leaf surface)comb-like

Common Name(s)

Comb sedge

Current Conservation Status

2012 - Not Threatened

Conservation status of New Zealand indigenous vascular plants, 2012
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2012 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2009 and replaces all previous NZTCS lists for vascular plants. Authors: Peter J. de Lange, Jeremy R. Rolfe, Paul D. Champion, Shannel P. Courtney, Peter B. Heenan, John W. Barkla, Ewen K. Cameron, David A. Norton and Rodney A. Hitchmough. File size: 792KB

Previous Conservation Status

2009 - Not Threatened
2004 - Not Threatened

Authority

Oreobolus impar Edgar

Family

Cyperaceae

Flora Category

Vascular - Native

NVS Species Code

OREIMP

The National Vegetation Survey (NVS) Databank is a physical archive and electronic databank containing records of over 94,000 vegetation survey plots - including data from over 19,000 permanent plots. NVS maintains a standard set of species code abbreviations that correspond to standard scientific plant names from the Ngä Tipu o Aotearoa - New Zealand Plants database.

Structural Class

Sedges

Synonyms

None

Distribution

Endemic. North, South and Stewart Islands. Confined to the Central Volcanic Plateau and adajcent main axial ranges in the North Island.

Habitat

Coastal to alpine (up to 1500 m a.s.l.). Mostly alpine descending to sea level only in the southern South and Stewart Islands. A species favouring permanently damp mineral soils within the ecotone of grassland and bog or shrubland and bog.

Features

Perennial sedge forming a compact whitish-green or yellowish-green mat 20-50 mm high. Stems densely packed. Leaves spreading, not obviously distichously; lamina 0.5-1.0 mm wide, channelled at the base, abruptly widening to the upper flat portion, abaxial surface rich in stomata with only the median nerve prominent, adaxial surface having no stomata except occasionally with a few present toward the apices or very near the margin, with two lateral nerves prominent and the median nerve occasionally extending towards the apex; sheath about twice the width of lamina, 5-7-nerved, without conspicuous auricles. Mature peduncle <, = or rarely > leaves, bearing 1-3 spikelets. Glumes 3, more or less equal, keel stiff and green, sides pale and membranous, often tinged with red. Hypogynous scales slightly > or = nut, very narrow-linear, white or pale brown. Stamens (2-)3. Nut slightly > 1 mm long, c.1 mm diameter, almost flat at the apex with a large depression, obovoid, shortly but distinctly stipitate, light grey.

Similar Taxa

Closest to O. strictus Bergg. from which it differs by the densely packed stems; leaves with stomata only on the undersides, and by the hypogynous scales > or occasionally equal in length to the nut. From O. pectinatus it differs by its compact mat-forming rather than cushion-forming growth habit, leaves usually not distichously arranged with only the median nerve visible on the leaf undersides at the widest part of the lamina; and by the usually red-tinged glumes.

Flowering

October - December

Fruiting

November - April

Propagation Technique

Easily grown from rooted pieces and probably from fresh seed. However, this species is best grown in a cooler climate or kept in a pot within an alpine house. it is very slow growing.

Threats

Not Threatened

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

Where To Buy

Not commercially available

Attribution

Description adapted from Moore and Edgar (1970).

References and further reading

Moore, L.B.; Edgar, E. 1970: Flora of New Zealand. Vol. II. Government Printer, Wellington.

This page last updated on 3 Jan 2014